Tubular-magazine automatic firearm



May l2, 1942.

C. G. SWEIBILIUS TUBULAR-MAGAZINE AUTOMATIC FIREARM Filed June 2l, 19393 Sheets-Sheet l May l2, 1942.

C. G. SWEBILUS TUBULAR-MAGAZINE AIUTOMATJIG FIREARM Filed June 21, 19593 Sheets-Sheet 2 MaylZ, 1942. c. G. swEBlLlUs 2,282,903

UBULAR-MAZINE AUTOMATIC FIREARM Filed June 21, 1959 5 Sheets-Sheet 3Patented May 12, 1942 UITED STT-ESA`V PATENT `FFICE TUBULAR-MAGAZINEAUTOMATIC FIREARM Application June 21, 1939, Serial No. 280,222

` 4 c1aims.(o1.42-17) This invention relates to improvements intubular-magazine automatic rearms, that is to say, iirearms havingtubular-magazines and a construction and arrangement of parts wherebythe discharge of one cartridge automatically ef-j fects the extractionand ejection of the justfired cartridge and the insertion of a freshcartridge into the cartridge-chamber of the rearm preparatory to anothercycle of operation.

One of the objects of the present invention.' 10 is to provide asuperior tubular-magazine automatic rearm characterized by novel andsuperior cartridge-elevating means to thus insure the proper automaticfeeding of a fresh cartridge into the cartridge-chamber of the firearm.315

Another object of the present invention is to provide an automaticfirearm of the type referred to in which reliable and eiiective means isprovided for insuring the one-by-one feeding of a column of cartridgesfrom a tubular-maga-F?o zine for insertion into the cartridge-chamber ofthe iirearm.

A further object of the present invention is to provide a superiortubular-magazine automatic firearm having a novel construction andarrangement of parts whereby the gases escaping rearwardly from thecartridge-chamber of the rearm when a just-red cartridge is extracted,will be permitted to escape in a manner which will not tend to clog thetubular-magazine nor subject the marksman to discomfort.

Still another object is to provide a rearm of the character described,with superior, reliable and eifective means for locking thering-mechanism of the firearm against release.

With the above and other objects in view, as will appear to thoseskilled in the art from the present disclosure, this invention includesal1 features in the said disclosure which are novel over the prior artand which are not claimed in any separate application.

In the accompanying drawings, in which certain modes of carrying out thepresent invention are shown for illustrative purposes: 4

Fig. 1 is a broken view in side elevation of a tubular-magazineautomatic iirearm embodying the present invention;

Fig. 2 is a broken view in vertical central-longitudinal section andpartly in side elevation, with the parts shown in the positions due tothem at an instant prior to the discharge of the rearm;

Fig. 3 is a similar view but showing the breechbolt in its fully retiredposition;

Fig. 4 is a transverse sectional view taken on the line 4-4 of Fig. 3;

Fig. 5 is a transverse sectional view taken on y the line 5-5 of Fig. 3;

Fig. 6 is a view in vertical central-longitudinal section of themounting-member and the parts carried thereby shown as detached from thereceiver;

Fig. 7 is a top or plan View thereof with a portion of thecartridge-guide plate broken away and shown in section;

Fig. 8 is an under side view thereof;

Fig. 9 is a transverse sectional view taken on the line 9-9 of Fig. 6;

Fig. 10 is a perspective view of one of the sideplates of themagazine-throat;

Fig. 1l is a perspective view of one of the cartridge-detent springs;and

Fig. 12 is a perspective view of the cartridgeelevating plate of themagazine-throat.

The particular tubular-magazine automatic rearm herein chosen for theillustration of the present invention includes three major components,namely, a receiver 20, a barrel 2| and a stock 22.

The receiver 20 has an ejection-opening 20a and is cylindricallycontoured exteriorly and has its forward end interiorly threaded for thethreaded connection of the exteriorly threaded rear portion of thebarrel 2|, which latter has a cartridge-chamber 2Ia. Extendingsubstantially throughout its length, the receiver 20 is formed with adownwardly-opening bolt-receiving chamber 23 having its upper halfcylindrically contoured to conform to the similarly-contoured upper halfof a reciprocating breech-bolt generally designated by the referencecharacter 24. The said breech-bolt 24 is retained in place in thebolt-receiving chamber 23 in the receiver 20 against downwarddisplacement therefrom, by a bar-like mounting-member generallydesignated by the reference character 25. The said mounting-memberprojects slightly upwardly into the lower portion of the bolt-receivingchamber 23 in the said receiver 20, as will be particularly wellobservable by reference to Figs. 4 and 5.

-The bar-like mounting-member 25 above referred to, includes twosubstantially-corresponding parallel side-plates 26 and 2l which arelaterally spaced from each other to provide a central longitudinal andvertical channel 28, by a rear spacing-block 29 and a frontspacing-block 30, as is shown in Figs. 6 to 9 inclusive.

The upper portion of the rear spacing-block 29 projects above the uppersurface of the sideextension 32 which Vabuts against the forward j faceof the rear-wall 33 of the receiver 2d and overhangs aforwardly-extending coupling-lip 32 projecting forwardly from the lowerportion of the said rear-wall 33. As thus arranged, the saidcoupling-extension il and the coupling-lip 3Q serve to normally preventthe downward movement of the rear portion of the mounting-member 25 withrespect to the bolt-receiving chamber 23 in the receiver 2d.

Projecting rearwardly from the rear spacingblock 29 of themounting-member 25 at the lower end thereof, is a coupling-lip B whichis adapted 'l to extend over a coupling-pin so extending transverselyacross the rear portion of a Vlongitudinally-extending upwardly-openingrecess 3i formed in the stock 22 before referred to. The saidcoupling-pin 36 thus forms a permanent feature of the stock 22.

To couple the forward portion of the bar-like mounting-member 25 to theassembly comprising the receiver 2d and the barrel 2l, the frontspacing-block Si) is formed with a forwardly-opening recess orcoupling-socket (Fig. 2) which is adapted to receive thecylindrically-contoured rear end 2Q of a coupling-screw di?. The saidcoupling-screw it is threadedly mounted in a block-likestock-attachinglug di depending from the rear` portion of the barrel 2land flxedly attached thereto by means of a dovetail connection 42. Thesaidstock-attaching lug lil has threaded into it the threaded upper endlof a stockattaching screw i3 which extends upwardly from the under faceof the stock 22 A.through an esserves to secure the forward portion ofthe said stock to the barrel 2l andk hence to the receiver 2Q and itsassociated parts. v

The receiver 2d, barrel 2| and mounting-mem-v ber 25 are so organized,as will be seen from the foregoing, as to constitute an assembly whichmay be separated as such from the stock 22. The parts 2Q, 2l and 25 maytherefore be termed a barrel-unit. l l

The breech-bolt 2d is provided with a longitudinal passage l5 in whichreciprocates a firingplunger or member d@ formed at its forward end witha firing-point ll-l adapted to impinge against and re a cartridge in thecartridgechamber of the barrel 2l in the usual manner of firearms.'4 Inits upper rear portion the firingplunger d is formed with aforwardly-facing cooking-abutment i8 which is releasably engaged bya'sear-nose [i3 located at the forward end of a sear 5d. The said searis mounted for pivotal movement upon a transverse pin iii mounted in thehead Sl of the rear spacing-block 29. The rearwardly-projecting portionof the sear Eil is pressed upwardlyV by a helical sear-spring :'52, asshown in Fig. 6.

Intermediate the sear-nose i3 and the pin 5l, .theY sear 52 is formedwith a downwardlyfacing actuating-abutment 53 which is adapted to beengaged by the upper end of the bodyportion 54. of a transmitting-membergenerally designated by the reference character 5%. The saidtransmitting-member 55 is pressed downwardly by a spring v55a and alsoincludes a forwardly-extending ringer having its forward '40, cutcheonifi mounted in the `said stock 22, and

end beveled to provide a forwardlyand upwardly-sloping cam-surface 5iwhich is engageable by a similarly-sloping disconnecting-cam 5B formedat the rear end of a clearance-passage EQ formed in a lug Si) dependingfrom the rear end of the breech-bolt 25. Y

The transmitting-member 55 is mounted with capacity for both verticalreciprocating movement and rocking movement in the rear spacingblock 2Qby means of a pin Si mounted in the said spacing-block and extendingthrough a vertical-slot in the lower portion of the bodyportion 5d ofthe said transmitting-member, as is shown inFig. 6. The under edge ofthe bodyportion of the transmitting-member 55 is adapted to he engagedand lifted by the upper end of a trigger generally designated by thereference character t3 and mounted for pivotal movement upon atransverse pin Eli mounted in the stock 22. rlhe said trigger is formedwith a ltubular-portion S5 through which a tubularmagazine housing Gliextends at an upwardlyand forwardly-sloping angle. The saidtubularmagazine housing is mounted in the stock 22 and houses amagazine-tube 5l which has a helical magaZine-spring GS (Fig. 2)pressing forwardly upon a cartridge-follower G9 which, in turn, pressesforwardly upon the rearmost one of a column of cartridges which may belocated in the magazine-tube lil and also such ofthose cartridges as maybe in process or being fed to the cartridge-chamber of the arm asexemplified by the cartridges 'iii and il shown in Figs. 2 andS.

Returning now to the breech-bolt 2li and the ming-plunger G5 which itcarries, it will be noted by reference to Fig. 2 that the saidring-plunger is formed with an axial rearwardly-opening bore l2 whichreceives the forward portion of a helical firing-spring i3 thrusting atits forward end against the end-wall of the bore 'l2 in the saidfiring-plunger. At its rear end the firing-spring 'i3 encircles aspring-guiding plunger 'lll which, in turn, is seated against theforward face of the head 3l of the rear spacing-block 29, and

^ which is adapted to be telescopically received in the bore 'l2 in theiiring-plunger 46.

For the purpose of yieldingly urging the breech-bolt 2d into itsbreech-closing position, a helical breech-closing spring l5 is providedwhich presses at its forward end against the rearV face of thebreech-bolt 212i. The said breech-closing spring l5 encircles aspring-guiding plunger 76 (Fig. 2) which is pressed rearwardly againstthe forward face of the head 3l of the rear spacing-block 29.

To provide for locking the transmitting-member 55 against upwardmovement to operate the sear 5l] and thus release the firing-plunger 46,a safety lock is providedV which comprises a cylindrical stem ll and afingerpiece i8 (Figs. 1, 2 and 3) riveted thereto. The said stem 'l'lextends transversely across the mounting-member 25 and is journaledtherein for oscillating movement while the ngerpiece i8 extends abovethe adjacent upper portion of the stock 22 and is accommodated in ashallow clearance-notch (Fig. l)r 29 formed in the side-wall of thereceiver 2li adjacent-the rear end thereof. At a point inline with thebody-portion 54 of the transmitting-member '55, the stem 'H is formedwith a clearance-notch Bil (Fig. 6) which, when in the position in whichit is shown by full lines in Fig. 6, providesclearance for the verticalmovement of the body-portion 54 of the transmitting-member 55 with theresult that the stem under these conditions does not in any wayinterfere with the free action of the said transmitting-member. When,however, the stem is turned so that its clearance-notch 80 is inclinedinto the position indicated by broken lines 8| in Fig. 6, a portion ofthe said stem will be projected into the path of movement of an arcuatestop-shoulder 82 formed upon the bodyportion 54 of thetransmitting-member 55, to thus prevent the said transmitting-memberfrom being lifted by the trigger 63. In this manner the firearm isrendered safe since it cannot be discharged under the conditions justreferred to.

Installed in the forward portion of the channel 28 of themounting-member 25 is a group of parts constituting a magazine throatwhich will now be described in detail. Y

The magazine throat above referred to includes two complementa]side-plates 83 and 84 extending longitudinally of the channel 28 in themounting-member 25 and respectively located against the inner faces ofthe side-plates 26 and 2l of the said mounting-member as is especiallywell shown in Figs. 7, 8 and 9. Each of the sideplates 83 and 54 isdiagonally sheared to provide an upwardlyand forwardly-slopingcartridgeelevating cam-surface 85 for the purpose as will more fullyhereinafter appear.

Forwardly of its cam-surface 85, each of the side-plates 83 and 84referred to, is formed with an in-struck rib 86 extending verticallythroughout the whole width of the side-plate of which it forms a partand resulting in the formation in the outer face of each of the saidside-plates of a vertical channel receiving a cartridge-detent spring8l. Each cartridge-detent spring 8l (of which there are two-one for eachside-plate) is provided at its upper end with an inwardly-projectingcartridge-detent nger 88 projecting inwardly through a clearance-notch89 formed in the upper edge of the complemental rib 86. The lower end ofeach of the cartridge-detent springs 81 is formed with an L-shapedretaining-finger 98, the horizontal portion of which is accommodated ina clearance-notch 9| one of which is formed in the lower edge of each ofthe ribs 86, as shown particularly well in Fig. 10.

Rigidly mounted intermediate the upper rear portions of the respectiveside-plates 83 and 84, is a cutoff-carrier 92 formed of sheet metal benttransversely into inverted U-shaped form. The said cut-off carrier 92accommodates a pivotal cartridge-cutoff 93 which is pivotally connectedat its rear end tc the said carrier 92 by means of a transverse pin 94.

Extending parallel with and located laterally intermediate theside-plates 83 and 84 is a cartridge-elevating plate 95 of substantiallythe shape of a right-angle triangle and having its upper face or edgesloping upwardly and forwardly away from the open end of themagazine-tube 61 in substantial parallelism therewith. The saidcartridge-elevating plate 95 is held in spaced relationship midwaybetween the side-plates 83 and 94 by means of spacing-collars 96 throughwhich extend pins 91 also extending through the said plate 95, theside-plates 83 and 84 as well as the side-plates 26 and 2l of themounting-member 25`.

As a result of the spacing between the sideplates 83 and 84 and thecartridge-elevating plate 95, two vertically-extending vent-passages98-98 are provided for permitting the escape of gases downwardly througha vent-passage 99 formed in the stock 22 centrally in line with andbeneath the mounting-member 2'5, as is shown especially .well in Figs.2, 3, 4 and 5, all for the purpose as will hereinafter appear Returningnow to the cartridge-cutoff 93, it

will be noted that the same is formed at its forward end with anactuating-nose |00 which is adapted to project upwardly through aclearanceopening |0| in the cutoff-carrier 92 for engagement with theunder side of the breech-bolt 24 and for entry into a clearance-notch|02 formed in the under side of the breech-bolt, as shown.

The cartridge-cutoff 93 is also formed on its under side with adownwardly-projecting cartridge-stopping finger |03 which is adapted tobe engaged by the forward face of the rims or heads |04 of thecartridges 10 and ll, as well as of such other cartridges as may beincluded in a column of cartridges, as the same sequentiallyv emergefrom the magazine-tube 67, all in a manner as will more fullyhereinafter appear.

The left or outer face of the side-plate 2l of the mounting-member 25 isformed at its forward end with a vertically-extending groove |05 inwhich is installed a cartridge-guiding plate |06 having aninwardly-turned flange |87 terminating at its rear end in anejecting-nger |98.

For the purpose of making clear the operation of the tubular-magazineautomatic firearm herein chosen for the illustration of the presentinvention, let it be assumed that the breech-bolt 24 is in itsbreech-closing position and that the cartridge |09 in thecartridge-chamber 2|aV of the barrel 2| has just been struck by thefiring-point 4l, as is shown in Fig. 2, and that the said cartridge 09is about to discharge.

The explosion of the cartridge |09 will move the breech-bolt 24rearwardly and also shift certain of the other features of the firearminto the positions in which they are shown in Fig. 3 of the accompanyingdrawings.

As the breech-bolt 24 moves rearwardly, the just-fired cartridge |09will be withdrawn from the cartridge-chamber 2|a of the barrel 2| andwill be brought into engagement with the ejecting-inger |98 and willthereby be ejected laterally outwardly through the ejection-opening 20ain the receiver 2'0 (Fig. l)

Inasmuch as the just-fired cartridge has supplied the energy to throwback the breech-bolt 24, its retraction from the cartridge-chamber 2 la,will be so rapid as to permit some of the gases and residue to blow backinto the space intermediate the rear end of the barrel 2| and theforward face of the breech-bolt 24. This gas and attendant residue will,however, be permitted to so freely escape downwardly through the vent-Apassages 98-98 in the fore-portion of the mounting-member 25 anddownwardly through the vent-passage 99 in the stock 22 as to effectivelypreclude the forcing of such gases and residue into the open end of themagazine-tube 6l, thus avoiding one of the major drawbacks to automaticrearms.

As soon as the breech-bolt 24, in its rearward travel, rides rearwardlyclear of the cartridge 7|, both of the cartridges 10 and will moveforwardly under the urge of the magazine-spring 68 until the rim |04 ofthe cartridge 19 comes into engagement with the cartridge-stopping nger|03 of the cartridge-cutoff 93, whereupon the forward movement of thecartridges will cease, since the said cartridge-cutoff 93 is now heldagainst upward swinging movement of its forward end by the engagement ofits actuatingnose mi? with the under face of the breech-bolt 2li, as isshown in Fig. 3. As the cartridge 'H is moved forwardly as justdescribed, it will also move upwardly in an inclined path, owing to theriding of its head or rim i535 along the inclined cam-surfaces Bri- 85of the respective side-plates 83 and 84 and will force thecartridge-detent fingers Sii- 88 apart. Simultaneously with the ridingof the rim or head iii of the cartridge 'il as just described, thebullet-end of the cartridge will ride up the incline provided by theupper edge of the cartridge-elevating plate 95.

From the foregoing description of the movement of the foremost one ofthe column of cartridges, it will be seen that the cartridge 1l, as wellas each of the following cartridges in sequence, will be elevated byelements acting at two spaced-apart points, so as to always occupy a vposition substantially parallel with the axis of the breech-bolt 26.

As thus elevated, the cartridge 'H is in position to be engaged by thefront face of the breech-bolt 24 when the said breech-bolt returns fromthe position in which it is shownv in Fig. 3 into its breech-closingposition as shown in Fig. 2. When the breech-bolt moves forwardly, asjust referred to, the cartridge 'H will be further elevated by thecoincidental action of both the cartridge-elevating cam-surfaces and theupper edge of the cartridge-elevating plate 95 and will be ultimatelyseated in the cartridge-chamberV Zia of the barrel 2i, preparatory tothe next discharge of the firearm.

While the foremost cartridge'il is being introduced into thecartridge-chamber 2id, and until the same is substantially fully seated,the cartridge lil will be restrained by the cartridge-cutoff 93 frommoving forwardly beyond ythe position in which it is shown in Fig.,3 andwill thus be restrained against moving into a position which might causea jam. As soon, however, as the breech-bolt 24 reaches substantially itsfull breech-closing position, the Vclearance-notch H32 in the under faceof the breech-bolt Zii will come into registration with theactuating-nose of the cartridge-cutoff, thus releasing the latter fromrestraint and permitting the magazinespring 68 to force the cartridgeill into the position formerly occupied by the cartridge il in F'ig. 2of the drawings.

It will be understood from the foregoing that when the breech-bolt isthrown backwardly by the discharge of a given cartridge, thecookingabutment liii of the firing-plunger 46 will be moved to the rearofthe scar-nose 49, as is shown in Fig. 3, and upon the return of thebreechbolt to its breech-closing position, the said firingplunger willbe restrained in its cocked position by the scar-nose is until such timeas the trigger 63 is actuated.

Should it be desired, for any reason, to lock the mechanism of thefirearm so that the ringplunger 46 cannot be released by a pull upon thetriggerY @3, the finger-piece 'i8 may be 'swung into the position inwhich it is indicated by broken lines in Fig. 1, to thus turn the stem'Vi so that its clearance-notch 8@ is turned into the position in whichit is indicated by broken lines in Fig. 6. In this latter position, thestem 'H is thus interposed in the path of movement of thetransmitting-member 55 and a pull upon the trigger 63 under thesecircumstances will merely seat the stop-shoulder B2 of the saidtransmitting-member against the said stem Ti.

The invention may be carried .out in Vother specic Ways than thoseherein set forth without departing from the spirit and essentialcharacteristics of the invention, and the present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and yequivalencyrange of the appended claims are verse of the firearm-structure and eachhaving on its inner face a forwardly-and-upwardly-inclinedcartridge-elevating surface positioned to be engaged by the rim of acartridge, a cartridgeelevating plate having aforwardly-and-upwardly-inclined upper edge and spaced intermediate thetwo lsaid side-plates, .and spacing-means holding the saidcartridge-elevating plate in substantial parallelism with the two saidsideplates and spaced away from the respective inner faces of eachthereof; and a tubular maga- 'zine located in the portion of the saidstock to the rear of the said receiver and having a cartridge-deliveryopening adjacent its forward end positioned to deliver cartridges to thespace between the two said side-plates of the said cartridge-elevatingmeans and upon the upper surface of the cartridge-elevating platethereof.

2. A tubular-magazine automatic rearrn including in combination: abarrel; a receiver-unit extending vrearwardly from the said barrel andhaving a downwardly-extending passage therein; a breech-boltreciprocating in the said receiver-unit; a stock associated with thesaid barrel and receiver and extending rearwardly beyond the latter;cartridge-elevating means located beneath the said breech-bolt in thedownwardlyextending passage in the said receiver-unit, the saidcartridge-elevating means comprising two vertical side-plates extendingsubstantially parallel with each other and spaced laterally from eachother in a direction transverse of the nrearm-structure and each pressedoutwardly .intermediate its respective opposite ends to provide aforwardly-and-upwardly-inclined cartridge-elevating channel positionedto receive the rim of a cartridge, a cartridge-elevating plate having aforwardly-and-upwardiy-inclined upper edge and spaced intermediate thetwo said side-plates, and spacing-means holding the saidcartridge-elevating plate in substantial parallelism with the two saidside-plates and spaced away from the respective inner faces of eachthereof; and a tubular magazine located in the portion of the said stockto the rear of the said receiver and having a cartridge-delivery openingadjacent its forward end positioned to deliver cartridges to the spacebetween the two said side-plates of the said cartridge-elevating meansand upon tne upper surface of the cartridge-elevating plate thereof.

3. A tubular-magazine automatic firearm in- H cluding in combination: abarrel; a receiver exing an open lower side a mounting-member removablysecured to the underside of the said receiver and comprising twolaterally-spacedapart side-plates; a breech-bolt reciprocating in thesaid receiver; a, stock associated with the said barrel, receiver andmounting-member and extending rearwardly beyond the said receiver;cartridge-elevating means located beneath the said breech-bolt andcomprising two vertical side-plates laterally spaced from each other ina direction transverse of the rearm and respectively located adjacentthe inner face of one of the two side-plates of the saidmounting-member, each of the side-plates of the cartridge-elevatingmeans having on its inner face a forwardly-and-upwardly inclinedcartridge elevating surface positioned to be engaged by the rim of acartridge, a cartridge-elevating plate having aforwardly-and-upwardly-inclined upper edge and spaced intermediate thetwo said side-plates, and spacing-means holding the saidcartridgeelevating plate in substantial parallelism with the two saidside-plates and spaced away from the respective inner face-s of eachthereof; and a tubular magazine located in the portion of the said stockto the rear of the said receiver and having a cartridge-delivery openingadjacent its forward end positioned to deliver cartridges to the spacebetween the two said side-plates of the said cartridge-elevating meansand upon the upper surface of the cartridge-elevating plate thereof.

4. A tubular-magazine automatic firearm including in combination: abarrel; a receiver extending rearwardly from the said barrel and havingan open lower side; a mounting-member removably secured to the undersideof the said receiver and comprising two laterally-spacedapartside-plates; a breech-bolt reciprocating in the said receiver; a stockassociated with the said barrel, receiver and mounting-member andextending rearwardly beyond the said receiver; cartridge-elevating meanslocated beneath the said breech-bolt and comprising two verticalsideplates laterally spaced from each other in a direction transverse ofthe firearm and respectively 1ocated adjacent the inner face of one ofthe two side-plates of the said mounting-member, each of the side-platesof the cartridge-elevating means being pressed outwardly intermediateits respective opposite ends to provide a forwardlyand-upwardly-inclinedcartridge-elevating channel positioned to receive the rim of acartridge, a cartridge-elevating plate having aforwardlyand-upwardly-inclined upper edge and spaced intermediate thetwo said side-plates, and spacingmeans holding the saidcartridge-elevating plate in substantial parallelism with the two saidsideplates and spaced away from the respective inner faces of eachthereof; and a tubular magazine located in the portion of the said stockto the rear of the said receiver and having a cartridge-delivery openingadjacent its forward end positioned to deliver cartridges to the spacebetween the two said side-plates of the said cartridge-elevating meansand upon the upper surface of the cartridge-elevating plate thereof.

A CARL G. SWEBILIUS.

